U.S. Pat. No. 3,947,473, Scott et al., discloses a compound ##STR1## wherein R.sub.1, R.sub.1 ', and R.sub.1 " are independently hydrogen or lower alkyl, and R.sub.2 is lower alkyl
and a method for resolving this compound into its two isomeric forms, i.e. ##STR2## wherein R.sub.1, R.sub.1 ', R.sub.1 " and R.sub.2 are as above. In many cases, it is desired to utilize the compound of formula I in its 2S form, i.e. the compound of formula I-B. This is especially true where R.sub.1, R.sub.1 ', R.sub.1 " and R.sub.2 are methyl since this compound is an intermediate for natural optically active alpha-tocopherol, i.e. alpha tocopherol having the 2R,4' R and 8'R configuration. Therefore, the compound of formula I-A may be the undesired isomer and the conversion to the optically pure 2S form be desired.